Adjustable devices for treating arthritis of the knee

ABSTRACT

A method of changing a bone angle includes creating an osteotomy between a first portion and a second portion of a tibia of a patient; creating a cavity in the tibia by removing bone material along an axis extending in a substantially longitudinal direction from a first point at the tibial plateau to a second point; placing a non-invasively adjustable implant into the cavity, the non-invasively adjustable implant comprising an adjustable actuator having an outer housing and an inner shaft, telescopically disposed in the outer housing, and a driving element configured to be remotely operable to telescopically displace the inner shaft in relation to the outer housing; coupling one of the outer housing or the inner shaft to the first portion of the tibia; coupling the other of the outer housing or the inner shaft to the second portion of the tibia; and remotely operating the driving element to telescopically displace the inner shaft in relation to the outer housing, thus changing an angle between the first portion and second portion of the tibia.

BACKGROUND OF THE INVENTION

Field of the Invention

The field of the invention generally relates to medical devices fortreating knee osteoarthritis.

Description of the Related Art

Knee osteoarthritis is a degenerative disease of the knee joint thataffects a large number of patients, particularly over the age of 40. Theprevalence of this disease has increased significantly over the lastseveral decades, attributed partially, but not completely, to the risingage of the population as well as the increase in obesity. The increasemay also be due to the increase in highly active people within thepopulation. Knee osteoarthritis is caused mainly by long term stresseson the knee that degrade the cartilage covering the articulatingsurfaces of the bones in the knee joint. Oftentimes, the problem becomesworse after a particular trauma event, but it can also be a hereditaryprocess. Symptoms include pain, stiffness, reduced range of motion,swelling, deformity, muscle weakness, and several others. Osteoarthritismay include one or more of the three compartments of the knee: themedial compartment of the tibiofemoral joint, the lateral compartment ofthe tibiofemoral joint, and the patellofemoral joint. In severe cases,partial or total replacement of the knee is performed in order toreplace the diseased portions with new weight bearing surfaces for theknee, typically made from implant grade plastics or metals. Theseoperations involve significant post-operative pain and requiresubstantial physical therapy. The recovery period may last weeks ormonths. Several potential complications of this surgery exist, includingdeep venous thrombosis, loss of motion, infection and bone fracture.After recovery, surgical patients who have received uni-compartmental ortotal knee replacement must significantly reduce their activity,removing running and high energy sports completely from their lifestyle.

For these reasons, surgeons are attempting to intervene early in orderto delay or even preclude knee replacement surgery. Osteotomy surgeriesmay be performed on the femur or tibia, in order to change the anglebetween the femur and tibia, and thus adjust the stresses on thedifferent portions of the knee joint. In closed wedge or closing wedgeosteotomy, an angled wedge of bone is removed, and the remainingsurfaces are fused together, creating a new improved bone angle. In openwedge osteotomy, a cut is made in the bone and the edges of the cut areopened, creating a new angle. Bone graft is often used to fill in thenew opened wedge-shaped space, and often, a plate is attached to thebone with bone screws. Obtaining the correct angle during either ofthese types of osteotomy is almost always suboptimal, and even if theresult is close to what was desired, there can be a subsequent loss ofthe correction angle. Some other complications experienced with thistechnique include nonunion and material failure.

SUMMARY OF THE INVENTION

In a first embodiment of the invention, a system for changing an angleof a bone of a subject includes an adjustable actuator having an outerhousing and an inner shaft, telescopically disposed in the outerhousing, a magnetic assembly configured to adjust the length of theadjustable actuator though axial movement of the inner shaft and outerhousing in relation to one another, a first bracket configured forcoupling to the outer housing, and a second bracket configured forcoupling to the inner shaft, wherein application of a moving magneticfield externally to the subject moves the magnetic assembly such thatthe inner shaft and the outer housing move in relation to one another.

In another embodiment of the invention, a system for changing an angleof a bone of a subject includes a magnetic assembly having aradially-poled magnet coupled to a shaft having external threads, and ablock having internal threads and coupled to the shaft, whereinrotational movement of the radially-poled magnet causes the shaft toturn and to move axially in relation to the block. The system furtherincludes an upper bone interface and a lower bone interface having anadjustable distance, wherein axial movement of the shaft in a firstdirection causes the distance to increase.

In another embodiment of the invention, a system for changing an angleof a bone of a subject includes a scissors assembly having first andsecond scissor arms pivotably coupled via a hinge, the first and secondscissor arms coupled, respectively, to upper and lower bone interfacesconfigured to move relative to one another. The system further includesa hollow magnetic assembly containing an axially moveable lead screwdisposed therein, wherein the hollow magnetic assembly is configured torotate in response to a moving magnetic field and wherein said rotationtranslations into axial movement of the lead screw. The system furtherincludes a ratchet assembly coupled at one end to the lead screw and atanother end to one of the first and second scissor arms, the ratchetassembly comprising a pawl configured to engage teeth disposed in one ofthe upper and lower bone interfaces, and wherein axial movement of thelead screw advances the pawl along the teeth and moves the upper andlower bone interfaces away from one another.

In another embodiment of the invention, a method of preparing a tibiafor implantation of an offset implant includes making a first incisionin the skin of a patient at a location adjacent the tibial plateau ofthe tibia of the patient, creating a first cavity in the tibia byremoving bone material along a first axis extending in a substantiallylongitudinal direction from a first point at the tibial plateau to asecond point, placing an excavation device within the first cavity, theexcavation device including a main elongate body and configured toexcavate the tibia asymmetrically in relation to the first axis,creating a second cavity in the tibia with the excavation device,wherein the second cavity communicates with the first cavity and extendssubstantially towards one side of the tibia, and removing the excavationdevice.

In another embodiment of the invention, a method of implanting anon-invasively adjustable system for changing an angle of the tibia of apatient includes creating an osteotomy between a first portion and asecond portion of the tibia, making a first incision in the skin of apatient at a location adjacent the tibial plateau of the tibia of thepatient, creating a first cavity in the tibia along a first axisextending in a substantially longitudinal direction from a first pointat the tibial plateau to a second point, placing an excavation devicewithin the first cavity, the excavation device configured to excavatethe tibia asymmetrically in relation to the first axis, creating asecond cavity in the tibia with the excavation device, wherein thesecond cavity extends substantially towards one side of the tibia,placing a non-invasively adjustable implant through the first cavity andat least partially into the second cavity, the non-invasively adjustableimplant comprising an adjustable actuator having an outer housing and aninner shaft, telescopically disposed in the outer housing, coupling theouter housing to the first portion of the tibia, and coupling the innershaft to the second portion of the tibia. In some embodiments, theimplant could also be adjusted invasively, such as minimally invasively.

In another embodiment of the invention, a method of preparing a bone forimplantation of an implant includes making a first incision in the skinof a patient, creating a first cavity in the bone by removing bonematerial along a first axis extending in a substantially longitudinaldirection from a first point at the tibial plateau to a second point,placing an excavation device within the first cavity, the excavationdevice including a main elongate body and configured to excavate thebone asymmetrically in relation to the first axis, the excavation devicefurther comprising an articulating arm having a first end and a secondend, the arm including a compaction surface, creating a second cavity inthe bone with the excavation device, wherein the second cavitycommunicates with the first cavity and extends substantially towards oneside of the bone, and removing the excavation device.

In another embodiment of the invention, a method of preparing a bone forimplantation of an implant includes making a first incision in the skinof a patient, creating a first cavity in the bone by removing bonematerial along a first axis extending in a substantially longitudinaldirection from a first point at the tibial plateau to a second point,placing an excavation device within the first cavity, the excavationdevice including a main elongate body and configured to excavate thebone asymmetrically in relation to the first axis, the excavation devicefurther comprising an articulating arm having a first end and a secondend, the arm including an abrading surface, creating a second cavity inthe bone with the excavation device, wherein the second cavitycommunicates with the first cavity and extends substantially towards oneside of the bone, and removing the excavation device.

In another embodiment of the invention, a method of preparing a bone forimplantation of an implant includes making a first incision in the skinof a patient, creating a first cavity in the bone by removing bonematerial along a first axis extending in a substantially longitudinaldirection from a first point at the tibial plateau to a second point,placing an excavation device within the first cavity, the excavationdevice including a main elongate body and configured to excavate thebone asymmetrically in relation to the first axis, the excavation devicefurther comprising a rotational cutting tool configured to be movedsubstantially towards one side of the bone while the rotational cuttingtool is being rotated, creating a second cavity in the bone with theexcavation device, wherein the second cavity communicates with the firstcavity and extends substantially towards one side of the bone, andremoving the excavation device.

In another embodiment of the invention, a system for changing an angleof a bone of a subject includes a non-invasively adjustable implantcomprising an adjustable actuator having an outer housing and an innershaft, telescopically disposed in the outer housing, the outer housingconfigured to couple to a first portion of the bone, and the inner shaftconfigured to couple to a second portion of the bone, a driving elementconfigured to move the inner shaft in relation to the outer housing, andan excavation device including a main elongate body configured to insertwithin a first cavity of the bone along a first axis, the excavationdevice configured to excavate the bone asymmetrically in relation to thefirst axis to create a second cavity communicating with the firstcavity, wherein the adjustable actuator is configured to be coupled tothe bone at least partially within the second cavity.

In another embodiment of the invention, a method of changing a boneangle includes creating an osteotomy between a first portion and asecond portion of a tibia of a patient; creating a cavity in the tibiaby removing bone material along an axis extending in a substantiallylongitudinal direction from a first point at the tibial plateau to asecond point; placing a non-invasively adjustable implant into thecavity, the non-invasively adjustable implant comprising an adjustableactuator having an outer housing and an inner shaft, telescopicallydisposed in the outer housing, and a driving element configured to beremotely operable to telescopically displace the inner shaft in relationto the outer housing; coupling one of the outer housing or the innershaft to the first portion of the tibia; coupling the other of the outerhousing or the inner shaft to the second portion of the tibia; andremotely operating the driving element to telescopically displace theinner shaft in relation to the outer housing, thus changing an anglebetween the first portion and second portion of the tibia.

In another embodiment of the invention, a system for changing an angleof a tibia of a subject having osteoarthritis of the knee includes anon-invasively adjustable implant comprising an adjustable actuatorconfigured to be placed inside a longitudinal cavity within the tibia,and having an outer housing and an inner shaft, telescopically disposedin the outer housing, the outer housing configured to couple to a firstportion of the tibia, and the inner shaft configured to couple to asecond portion of the tibia, the second portion of the tibia separatedat least partially from the first portion of the tibia by an osteotomy;and a driving element comprising a permanent magnet and configured to beremotely operable to telescopically displace the inner shaft in relationto the outer housing.

In another embodiment of the invention, a system for changing an angleof a bone of a subject includes a non-invasively adjustable implantcomprising an adjustable actuator having an outer housing and an innershaft, telescopically disposed in the outer housing, the outer housingassociated with a first anchor hole, and the inner shaft associated witha second anchor hole, the first anchor hole configured to pass a firstanchor for coupling the adjustable actuator to a first portion of thebone and the second anchor hole configured to pass a second anchor forcoupling the adjustable actuator to a second portion of the bone, thesecond portion of the bone separated at least partially from the firstportion of the bone by an osteotomy; a driving element configured to beremotely operable to telescopically displace the inner shaft in relationto the outer housing; and wherein the non-invasively adjustable implantis configured to be angularly unconstrained in relation to at least oneof the first portion of the bone or the second portion of the bone whencoupled to both the first portion and second portion of the bone.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the desired alignment of a knee joint in relation toa femur and tibia.

FIG. 2 illustrates a knee joint with misalignment and associated medialcompartment osteoarthritis.

FIG. 3 illustrates an open wedge technique in a tibia.

FIG. 4 illustrates an open wedge technique with bone graft and a plateattached.

FIG. 5 illustrates a non-invasively adjustable wedge osteotomy deviceplaced in a tibia according to a first embodiment of the presentinvention placed in a tibia.

FIG. 6 illustrates a view of the non-invasively adjustable wedgeosteotomy device of FIG. 5.

FIG. 7 illustrates a detailed view of the lower clip of thenon-invasively adjustable wedge osteotomy device of FIGS. 5 and 6.

FIG. 8 illustrates an embodiment of a magnetically adjustable implant.

FIG. 9 illustrates a non-invasively adjustable wedge osteotomy devicebased on a spring element according to a second embodiment of thepresent invention.

FIG. 10 illustrates a non-invasively adjustable wedge osteotomy devicebased on a linked lift according to a third embodiment of the presentinvention.

FIG. 11 illustrates the non-invasively adjustable wedge osteotomy deviceof FIG. 9 being inserted into a wedge opening in a tibia.

FIG. 12 illustrates a non-invasively adjustable wedge osteotomy devicebased on a scissor jack according to a fourth embodiment of the presentinvention.

FIG. 13 illustrates the non-invasively adjustable wedge osteotomy deviceof FIG. 12 with the upper bone interface removed to show the scissorjack mechanism.

FIG. 14 illustrates a sectional view of the non-invasively adjustablewedge osteotomy device of FIGS. 12 and 13.

FIG. 15 illustrates a perspective view of an external adjustment device.

FIG. 16 illustrates an exploded view of a magnetic handpiece of theexternal adjustment device of FIG. 15.

FIG. 17 illustrates a non-invasively adjustable wedge osteotomy deviceaccording to a fifth embodiment of the present invention.

FIG. 18 illustrates a sectional view of the non-invasively adjustablewedge osteotomy device of FIG. 17.

FIG. 19 illustrates an exploded view of the non-invasively adjustablewedge osteotomy device of FIG. 17.

FIGS. 20-27 illustrate a method of implanting and operating anon-invasively adjustable wedge osteotomy device for maintaining oradjusting an angle of an opening wedge osteotomy of the tibia of apatient.

FIG. 28 illustrates distraction axes in a tibia.

FIGS. 29-31 illustrate a method of implanting and operating anon-invasively adjustable wedge osteotomy device for maintaining oradjusting an angle of a closing wedge osteotomy of the tibia of apatient.

FIG. 32 illustrates a system for excavation of bone material accordingto a first embodiment of the present invention.

FIG. 33 illustrates a rotational cutting tool of the system of FIG. 32.

FIG. 34 illustrates a side view of the rotational cutting tool of FIG.33.

FIG. 35 illustrates a section view of the rotational cutting tool ofFIG. 34, taken along line 35-35.

FIG. 36 illustrates a drive unit of the system of FIG. 32 with coversremoved.

FIG. 37 illustrates the system of FIG. 32 in place within a tibia.

FIG. 38 illustrates the system of FIG. 32 after removing bone materialfrom the tibia.

FIG. 39 illustrates a system for excavation of bone material accordingto a second embodiment of the present invention in place within thetibia.

FIG. 40 illustrates the system of FIG. 39 in an expanded configurationwithin the tibia.

FIG. 41 illustrates an end view of an arm having an abrading surface aspart of an excavation device of the system of FIG. 39.

FIG. 42 illustrates a system for excavation of bone material accordingto a third embodiment of the present invention in place within thetibia.

FIG. 43 illustrates the system of FIG. 42 in an expanded configurationwithin the tibia.

FIG. 44 illustrates an end view of an arm having a compaction surface aspart of an excavation device of the system of FIG. 42.

FIG. 45A illustrates a non-invasively adjustable wedge osteotomy deviceaccording to a sixth embodiment of the present invention.

FIG. 45B illustrates the non-invasively adjustable wedge osteotomydevice of FIG. 45A in a perspective view.

FIG. 46 illustrates a detailed view of the non-invasively adjustablewedge osteotomy device of FIG. 45B taken from within circle 46.

FIG. 47 illustrates the non-invasively adjustable wedge osteotomy deviceof FIG. 45A in a first distraction position.

FIG. 48 illustrates the non-invasively adjustable wedge osteotomy deviceof FIG. 45A in a second distraction position.

FIG. 49 illustrates a sectional view of the non-invasively adjustablewedge osteotomy device of FIG. 45A in a first distraction position.

FIG. 50 illustrates a sectional view of the non-invasively adjustablewedge osteotomy device of FIG. 45A in a second distraction position.

FIG. 51 illustrates a bushing of the non-invasively adjustable wedgeosteotomy device of FIG. 45A.

FIGS. 52-55 illustrate a method of implanting and operating thenon-invasively adjustable wedge osteotomy device of FIG. 45A formaintaining or adjusting an angle of an opening wedge osteotomy of thetibia of a patient.

FIGS. 56A-56D illustrate bone screw configurations for thenon-invasively adjustable wedge osteotomy device of FIG. 45A.

FIG. 57 illustrates a non-invasively adjustable wedge osteotomy deviceaccording to a seventh embodiment of the present invention.

FIG. 58 illustrates a bone anchor for use with the non-invasivelyadjustable wedge osteotomy device of FIG. 57.

FIGS. 59-61 illustrate a method of implanting and operating thenon-invasively adjustable wedge osteotomy device of FIG. 57 formaintaining or adjusting an angle of an opening wedge osteotomy of thetibia of a patient.

FIG. 62 illustrates a non-invasively adjustable wedge osteotomy deviceaccording to an eighth embodiment of the present invention in a firstdistraction position.

FIG. 63 illustrates the non-invasively adjustable wedge osteotomy deviceof FIG. 62 in a second distraction position.

FIG. 64A illustrates a magnetically adjustable actuator of anon-invasively adjustable wedge osteotomy device according to anembodiment of the present invention during removal of a magneticassembly.

FIG. 64B illustrates the magnetically adjustable actuator of FIG. 64Aafter removal of a magnetic assembly.

FIG. 64C illustrates the magnetically adjustable actuator FIG. 64A afterreplacement of an actuator housing cap.

FIG. 65A illustrates a magnetically adjustable actuator of anon-invasively adjustable wedge osteotomy device according to anembodiment of the present invention prior to removal of a radially-poledpermanent magnet.

FIG. 65B illustrates the magnetically adjustable actuator of FIG. 65Aduring removal of the radially-poled permanent magnet.

FIG. 65C illustrates the magnetically adjustable actuator of FIG. 64Aafter removal of the radially-poled permanent magnet and replacement ofa magnetic housing cap.

FIG. 65D illustrates the magnetically adjustable actuator of FIG. 64Aafter replacement of an actuator housing cap.

FIGS. 66-69 schematically illustrate various embodiments of alternatesources of a driving element of a non-invasively adjustable wedgeosteotomy device.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

FIG. 1 illustrates a standard alignment of a femur 100, a tibia 102 anda knee joint 104, wherein a hip joint (at a femur head 108), a kneejoint 104 and an ankle joint (at the midline of distal tibia 110) areoriented along a single line 112. A fibula 106 is shown alongside thetibia 102. The knee joint 104 of FIG. 2 is shown in an arthritic state,in which a medial compartment 114 has been compromised, causing the line112 to pass medially off the center of the knee joint 104.

FIG. 3 illustrates an open wedge osteotomy 118 formed by making a cutalong a cut line 120, and opening a wedge angle α. FIG. 4 illustratesthe final setting of this open wedge by the placement of bone graftmaterial 122 within the open wedge osteotomy 118, and then placement ofa plate 124, which is then secured to the tibia 102 with tibial screws126.

FIG. 5 illustrates a tibia 102 with a non-invasively adjustable wedgeosteotomy device 128 implanted. The non-invasively adjustable wedgeosteotomy device 128 is shown without the tibia 102 in FIG. 6. Thenon-invasively adjustable wedge osteotomy device 128 includes anactuator 142 comprising an outer housing 130 and an inner shaft 132telescopically coupled within the outer housing 130 for non-invasivelongitudinal adjustment. To implant the non-invasively adjustable wedgeosteotomy device 128, a hole 138 is drilled in the tibia 102, and then acut is made along cut line 120. The actuator 142 is then inserted,distal end 140 first, into the hole 138. A wedge opening 144 is openedenough to be able to insert a lower bracket 136 and an upper bracket134. The lower bracket 136, as seen in FIG. 7, has an opening 146 and aninternal diameter 148 which allow it to be snapped onto acircumferential groove 150 around the outer housing 130. The lowerbracket 136 is then secured to the tibia 102 at the lower portion 152 ofthe wedge opening 144 by placing bone screws (not shown) through screwholes 154. Upper bracket 134 is then slid into place and secured to aproximal end 156 of the actuator 142 by tightening a tightening screw158 which threads through a threaded hole in inner shaft 132 of theactuator 142. The upper bracket 134 is then secured to the tibia 102 atthe upper portion 162 of the wedge opening 144 by placing bone screws(not shown) through screw holes 164.

FIG. 8 illustrates a magnetically adjustable actuator 142 which can beused in the embodiments of FIGS. 5-7, or other embodiments describedherein. An inner shaft 132, having an end 160, is telescopicallyadjustable within an outer housing 130 by the use of a magnetic assembly166 contained therein. The magnetic assembly 166 comprises aradially-poled, cylindrical magnet 168 which engages with one or moreplanetary gear stages 170. The planetary gear stages 170 output to alead screw 172. In some embodiments, the final gear stage 170 may bepinned to the lead screw 172 with a high strength pin, for example, apin constructed from 400 series stainless steel. The inner shaft 132contains a cavity 174 into which is bonded a nut 176 having a femalethread which interfaces with the male thread of the lead screw 172. Aradial bearing 178 and a thrust bearing 180 allow the magnetic assembly166 to operate with relatively low friction. An o-ring seal 182 is heldwithin a circumferential groove on inside of the wall of the outerhousing 130, and the inner diameter of the o-ring seal 182 dynamicallyseals the outer diameter of the inner shaft 132.

Returning to FIG. 5, the non-invasively adjustable wedge osteotomydevice 128 is used to gradually open the wedge opening 144 over time. Byapplying a moving magnetic field from an external location relative tothe patient, for example, after the patient has recovered from surgery,the actuator 142 of FIG. 6 can be gradually lengthened (for exampleabout one (1) mm per day), allowing the wedge opening 144 to reach adesired angle, which can be tested by having the patient performdifferent motion studies (stepping, turning, etc.), until the mostcomfortable condition is reached. Gradual lengthening can allow for thepossibility of Ilizarov osteogenesis, in which new bone material formsin the wedge opening as it is opened. In such manner, a bone graft maybe unnecessary. After the desired wedge opening 144 angle is reached,the newly grown bone material can be allowed to consolidate. If, duringthe process, lengthening has been too rapid, or new bone has notconsolidated sufficiently, a moving magnetic field may be applied in anopposite direction thereby shortening the actuator 142 to addcompression and create a good dimension for callus formation. Afterconfirming that sufficient callus formation has taken place, lengtheningmay be resumed at the same speed, or at a different speed. Oncelengthening is sufficiently completed, and consolidated bone is stable,it may be desired to remove the entire non-invasively adjustable wedgeosteotomy device 128, or simply the magnetic assembly 166.

FIG. 9 illustrates a non-invasively adjustable wedge osteotomy device184 comprising magnetic assembly 192 including a magnet, e.g., aradially-poled cylindrical magnet 186 which is coupled to a drive screw188. As radially-poled cylindrical magnet 186 is turned by an externallyapplied moving magnetic field, the drive screw 188 turns inside a block190 having a female thread, causing the drive screw 188 and magneticassembly 192 to be moved in a first axial direction (A). As the magneticassembly 192 moves axially it pushes a curved shape memory (e.g.,superelastic Nitinol®) plate spring 194 at connection point 196. Athrust bearing 198 at the connection point 196 allows for continuedrotation of the radially-poled cylindrical magnet 186 as the forceincreases. As an inner curve 200 of the Nitinol plate spring 194 ispushed in the first axial direction (A), the width (W) of the Nitinolplate spring 194 increases. A cutout 202 in the Nitinol plate spring 194provides space for the radially-poled cylindrical magnet 186 to turn andto move in the first axial direction (A).

FIG. 10 illustrates a non-invasively adjustable wedge osteotomy device216 similar to the non-invasively adjustable wedge osteotomy device 184of FIG. 9, except that the Nitinol plate spring 194 of FIG. 9 isreplaced by a linked lift 204. Linked lift 204 comprises a lower plate206 and an upper plate 208 which are attached to a block 190 by pins 210which allow each plate 206 and 208 to increase in angulation alongarrows (B). Plates 206 and 208 are attached to inner plates 212 and 214by pins 210. The hinged structure of inner plates 212, 214 is pushedforward in a similar manner as Nitinol plate spring 194 is pushed in thefirst axial direction (A) in FIG. 9.

FIG. 11 illustrates the non-invasively adjustable wedge osteotomy device184 being placed into a wedge opening 144 in a tibia 102. Thenon-invasively adjustable wedge osteotomy device 216 of FIG. 10 can beinserted in the same manner.

FIGS. 12-14 illustrate a non-invasively adjustable wedge osteotomydevice 218 based on a scissor jack. Non-invasively adjustable wedgeosteotomy device 218 comprises a main housing 220 having a lower boneinterface 222 and an upper bone interface 224, the upper bone interface224 which can be adjusted with respect to the main housing 220 and thelower bone interface 222. FIG. 13 shows the non-invasively adjustablewedge osteotomy device 218 with the upper bone interface 224 removed tobetter appreciate the inner components. A scissors assembly 225comprises a first scissor 226 and a second scissor 228 that can becoupled by a center pin 230 in a hinged manner. Distal arms 234 and 238of scissors 226 and 228 can be coupled to the distal ends of the lowerbone interface 222 and the upper bone interface 224 by pins 240. An arm232 of the second scissor 228 is coupled to an interconnect 242 of amagnetic assembly 244 with a pin 240. A hollow magnetic assembly 246 hasinternal threads 247 which engage external threads 249 of a lead screw248 which is bonded to the interconnect 242. The hollow magneticassembly 246 may comprise a hollow radially-poled magnet. Theinterconnect 242 includes a pawl 251, which is able to engage teeth 253of a ratchet plate 255. As an externally applied moving magnetic fieldcauses the magnet 246 to rotate, the lead screw 248 and the interconnect242 are moved in a first axial direction (A), causing scissors assembly225 to open up, and thus increase the distance (D) between the lowerbone interface 222 and the upper bone interface 224. An arm 236 of thefirst scissor 226 is able to slide within a channel 257 in the upperbone interface 224. The pawl 251 and the teeth 253 of the ratchet plate255 form a one way ratchet, allowing the distance (D) to be increasedbut not decreased.

FIG. 15 illustrates an external adjustment device 1180 which is used tonon-invasively adjust the devices and systems described herein. Theexternal adjustment device 1180 comprises a magnetic handpiece 1178, acontrol box 1176 and a power supply 1174. The control box 1176 includesa control panel 1182 having one or more controls (buttons, switches ortactile, motion, audio or light sensors) and a display 1184. The display1184 may be visual, auditory, tactile, the like or some combination ofthe aforementioned features. The external adjustment device 1180 maycontain software which allows programming by the physician.

FIG. 16 shows the detail of the magnetic handpiece 1178 of the externaladjustment device 1180. As seen in FIG. 16, there are a plurality of,e.g., two (2), magnets 1186 that have a cylindrical shape (also, othershapes are possible). The magnets 1186 can be made from rare earthmagnets, and can in some embodiments be radially poled. The magnets 1186are bonded or otherwise secured within magnetic cups 1187. The magneticcups 1187 include a shaft 1198 which is attached to a first magnet gear1212 and a second magnet gear 1214, respectively. The orientation of thepoles of each the two magnets 1186 are maintained in relation to eachother by means of the gearing system (by use of center gear 1210, whichmeshes with both first magnet gear 1212 and second magnet gear 1214). Inone embodiment, the north pole of one of the magnets 1186 turnssynchronously with the south pole of the other magnet 1186, at matchingclock positions throughout a complete rotation. The configuration hasbeen known to provide an improved delivery of torque, for example tocylindrical magnet 168 or magnet 246. Examples of methods andembodiments of external adjustment devices that may be used to adjustthe non-invasively adjustable wedge osteotomy device 218, or otherembodiments of the present invention, are described in U.S. Pat. No.8,382,756, the disclosure of which is hereby incorporated by referencein its entirety, and U.S. patent application Ser. No. 13/172,598 whichwas published with publication number 2012-0004494 A1, the disclosure ofwhich is hereby incorporated by reference in its entirety.

The components of the magnetic handpiece 1178 are held together betweena magnet plate 1190 and a front plate 1192. Most of the components areprotected by a cover 1216. The magnets 1186 rotate within a staticmagnet cover 188, so that the magnetic handpiece 1178 may be resteddirectly on the patient, while not imparting any motion to the externalsurfaces of the patient. Prior to distracting the intramedullarylengthening device 1110, the operator places the magnetic handpiece 1178over the patient near the location of the cylindrical magnet 1134. Amagnet standoff 1194 that is interposed between the two magnets 1186contains a viewing window 1196, to aid in the placement. For instance, amark made on the patient's skin at the appropriate location with anindelible marker may be viewed through the viewing window 1196. Toperform a distraction, the operator holds the magnetic handpiece 1178 byits handles 1200 and depresses a distract switch 1228, causing motor1202 to drive in a first direction. The motor 1202 has a gear box 1206which causes the rotational speed of an output gear 1204 to be differentfrom the rotational speed of the motor 1202 (for example, a slowerspeed). The output gear 1204 then turns a reduction gear 1208 whichmeshes with center gear 1210, causing it to turn at a differentrotational speed than the reduction gear 1208. The center gear 1210meshes with both the first magnet gear 1212 and the second magnet gear1214 turning them at a rate which is identical to each other. Dependingon the portion of the body where the magnets 1186 of the externaladjustment device 1180 are located, it is desired that this rate becontrolled, to minimize the resulting induced current density impartedby magnet 1186 and cylindrical magnet 1134 though the tissues and fluidsof the body. For example a magnet rotational speed of 60 RPM or less iscontemplated although other speeds may be used such as 35 RPM or less.At any time, the distraction may be lessened by depressing the retractswitch 1230, which can be desirable if the patient feels significantpain, or numbness in the area holding the device.

FIGS. 17-19 illustrate a non-invasively adjustable wedge osteotomydevice 300 comprising a magnetically adjustable actuator 342 having afirst end 326 and a second end 328. An inner shaft 332 having a cavity374 is telescopically coupled within an outer housing 330, whichcomprises a distraction housing 312 and a gear housing 306. At least onetransverse hole 305 passes through an end cap 302 located at the firstend 326 of the magnetically adjustable actuator 342. The end cap 302 maybe sealably secured to the gear housing 306 by a circumferential weldjoint 390. A second weld joint 392 sealably secures the distractionhousing 312 to the gear housing 306. One or more transverse holes 364pass through the inner shaft 332. The one or more transverse holes 364and the at least one transverse hole 305 allow passage of at least onelocking screw. Some embodiments use only one transverse hole 364 and onetransverse hole 305 in order to better allow rotational play between themagnetically adjustable actuator 342 and the locking screws as themagnetically adjustable actuator 342 is adjusted. One or morelongitudinal grooves 372 in the outer surface of the inner shaft 332engage in a keyed manner with protrusions 375 in an anti-rotation ring373 which engages undercuts within end of the distraction housing 312 ata flat edge 384 of the anti-rotation ring 373. One or more guide fins383 in the anti-rotation ring 373 can keep the anti-rotation ring 373rotationally static within cuts 391 in the distraction housing 312.

The contents of the magnetically adjustable actuator 342 are protectedfrom body fluids by one or more o-rings 334 which reside withincircumferential grooves 382 in the inner shaft 332, dynamically sealingalong the inner surface of the distraction housing 312. The inner shaft332 is driven axially with respect to the outer housing 330 by a leadscrew 348 which is turned by a cylindrical radially poled magnet 368.The cylindrical radially poled magnet 368 is bonded within a firstmagnet housing 308 and a second magnet housing 310 and is rotatably heldat a pin 336 on one end by a radial bearing 378, which directly engagesthe counterbore 304 of the end cap 302. The second magnet housing 310outputs into a first stage 367 of three planetary gear stages 370. Theplanet gears 387 of the three planetary gear stages 370 turn withininner teeth 321 within the gear housing 306. The first stage 367 outputsto a second stage 369, and the second stage 369 outputs to a third stage371. The third stage 371 is coupled to the lead screw 348 by a lockingpin 385, which passes through holes 352 in both the output of the thirdstage 371 and in the lead screw 348. A lead screw coupler 339 is alsoheld to the lead screw 348 by the pin 385, which passes through a hole359. The lead screw 348 threadingly engages with a nut 376 which isbonded within the cavity 374 of the inner shaft 332. Each planetary gearstage 370 incorporates a 4:1 gear ratio, producing an overall gear ratioof 64:1, so that 64 turns of the cylindrical radially poled magnet 368cause a single turn of the lead screw 348. A thrust bearing 380, is heldloosely in the axial direction between ledges in the gear housing 306.The lead screw coupler 339 includes a ledge 355, which is similar to anopposing ledge (not shown) at the base of the lead screw 348. If theinner shaft 332 is retracted to the minimum length, the ledge at thebase of the lead screw 348 abuts the ledge 355 of the lead screwcoupler, assuring that the lead screw 348 cannot be jammed against thenut with too high of a torque. The thrust bearing 380 is held between aledge 393 in the gear housing 306 and an insert 395 at the end of thegear housing 306. The thrust bearing 380 serves to protect thecylindrical radially poled magnet 368, the planetary gear stages 370,the magnet housings 308 and 310, and the radial bearing 378 from damagedue to compression. A maintenance member 346 comprising a thin arc ofmagnetic material, such as ‘400 series’ stainless steel, is bondedwithin the gear housing 306, adjacent to the cylindrical radially poledmagnet 368, and can attract a pole of the cylindrical radially poledmagnet 368, in order to minimize the chance of the cylindrical radiallypoled magnet 368 turning when not being adjusted by the externaladjustment device 1180, for example during patient movement.

The non-invasively adjustable wedge osteotomy device 300 has thecapability to increase or decrease its length at least about threemillimeters in each direction in one embodiment, and about ninemillimeters in each direction in another embodiment. The non-invasivelyadjustable wedge osteotomy device 300 can achieve a distraction force of240 pounds when the magnetic handpiece 1178 of the external adjustmentdevice 1180 is placed so that the magnets 1186 are about one-half inchfrom the cylindrical radially poled magnet 368. The majority of thecomponents of the non-invasively adjustable wedge osteotomy device maybe made from Titanium or Titanium alloys such as Titanium-6Al-4V, CobaltChromium, Stainless Steel or other alloys. When implanted, thenon-invasively adjustable wedge osteotomy device 300 may be inserted byhand or may be attached to an insertion tool (for example a drillguide). An interface 366 comprising an internal thread 397 is located inthe end cap 302 for reversible engagement with the male threads of aninsertion tool. Alternatively, these features may be located on the end360 of the inner shaft 332. Additionally a detachable tether may beattached to either end of the non-invasively adjustable wedge osteotomydevice 300, so that it may be easily removed if placed incorrectly.

FIGS. 20 through 27 illustrate a method of implanting and operating anon-invasively adjustable wedge osteotomy device 125 for changing anangle of the tibia of a patient. In FIG. 20, a front view of the rightknee joint 104 of a patient with osteoarthritis of the knee is shown,including the femur 100, tibia 102 and fibula 106. The non-invasivelyadjustable wedge osteotomy device 125 can be placed towards the medialside of the tibia 102 (away from the fibula 106). The bone of the tibia102 is thus prepared to allow a non-central placement of thenon-invasively adjustable wedge osteotomy device. An incision is made inthe skin at a medial side of the tibia 102 and an open wedge osteotomy118 is made in relation to a hinge point 107, by creating a first cut103, for example with an oscillating saw, and opening the open wedgeosteotomy 118, as seen in FIG. 21. A typical location for the hingepoint 107 may be described by the distances X and Y in FIG. 20. In someembodiments, X=10 mm and Y=15 mm. At the hinge point, it is common tomake a small drill hole and place an apex pin, for example an apex pinwith a diameter of about 3 mm to about 4 mm. The open wedge osteotomy118 now separates a first portion 119 and second portion 121 of thetibia 102.

As seen in FIG. 22, an incision is made in the skin, a drill 111 isplaced at the central tibial plateau 101 and a first cavity 109 having afirst axis 117 is drilled from the tibial plateau 101 down the medullarycanal of the tibia 102. It may be desired during this drilling step toplace a temporary wedge 123 in the open wedge osteotomy 118, in order tomaintain stability. A drill diameter of about 12 mm or less, or morepreferably about 10 mm or less is used to create the first cavity 109.FIGS. 23 and 24 illustrate generalized steps for creating a secondcavity 115. Several embodiments are represented here by an excavationdevice 113, which is inserted into the first cavity 109 through theopening at the tibial plateau 101. The second cavity 115 is then formedto one side of the first cavity 109, in this case the medial side. Asshown in FIG. 25, after the excavation device 113 has been removed, anon-invasively adjustable wedge osteotomy device 125 having an outerhousing 129 and an inner shaft 127 is inserted into the first cavity109. In FIG. 25, the non-invasively adjustable wedge osteotomy device125 is shown with the inner shaft 127 facing superiorly (up) on thepatient, but it may desired in some situations to implant thenon-invasively adjustable wedge osteotomy device 125 with the innershaft 127 facing inferiorly (down). First transverse hole 135 and secondtransverse hole 137 in the non-invasively adjustable wedge osteotomydevice 125 are configured for placement of bone anchors, for examplelocking screws.

In FIG. 26, the non-invasively adjustable wedge osteotomy device 125 isthen placed into the second cavity 115 and secured with a first anchor131 through first transverse hole 135 and a second anchor 133 throughsecond transverse hole 137. Based on calculations made from pre-surgeryand/or surgery x-rays or other images, a wedge angle α₁ is set betweenthe first portion 119 and second portion 121 of the tibia. Afterpost-surgical recovery, the patient may return for a dynamic imagingsession (for example x-ray) during which the patient stands, and evenmoves the knee joint 104, in order to best confirm whether the wedgeangle α₁ is allows for the optimal conformation of the knee joint 104.If, for example, at this time it is desired to increase the wedge angleα₁, the magnetic handpiece 1178 of the external adjustment device 1180of FIG. 15 is then placed over the knee joint 104 of the patient andoperated so that the inner shaft 127 is distracted from the outerhousing 129, to increase to a larger wedge angle α₂ (FIG. 27). It may bedesired for at least one of the anchors (for example second anchor 133)to have enough clearance in the transverse hole (for example the secondtransverse hole 137) so that any angulation that occurs while thenon-invasively adjustable wedge osteotomy device 125 is distracted, willnot put an additional bending moment on the non-invasively adjustablewedge osteotomy device 125. The dynamic imaging session may be done at atime following surgery when swelling has decreased, but before boneconsolidation is significant. This period may be approximately one totwo weeks following surgery. If an adjustment is made (increase ordecrease), an additional dynamic imaging session may be performed, forexample, a week later. The non-invasively adjustable wedge osteotomydevice 125 is supplied so that it can be either lengthened or shortened,in other words, so that the angle of the open wedge osteotomy 118 may besubsequently increased or decreased, depending on the determination ofthe desired correction.

An alternative manner of quantifying the amount of opening of the openwedge osteotomy 118, is to measure, for example via radiography, the gapG₁, G₂ at the medial edge 181 of the open wedge osteotomy 118. At thetypical range of angles of open wedge osteotomies 118, and the typicalrange of patient tibia 102 sizes, the gap G₁, G₂, in millimeters tendsto approximate the wedge angle α₁, α₂ in degrees. For example, G₁(mm)≈α₁ (°); G₂ (mm)≈α₂ (°). It is expected that, assuming correction isrequired, productive lengthening will be done at a rate in the range ofabout 2 mm gap (G) increase per day or less. Gap increase rate (GIR) maybe defined as the change in gap in millimeters per day. Oneconsideration in determining the gap increase rate (GIR) to use is thepain tolerance of the patient. Some patients may tolerate a largeramount of pain, for example the pain caused by stretching of softtissue, and thus a higher gap increase rate (GIR). Another considerationis the amount of bone growth that is occurring. One method of assessingthe amount of bone growth is via radiography. The preferred gap increaserate (GIR) is that at which bone growth is occurring within the openwedge osteotomy 118, but early consolidation of the bone is notoccurring (consolidation that would “freeze” the mobility of the openwedge osteotomy 118, making it unable to be opened more). It may bedesired to purposely implant the non-invasively adjustable wedgeosteotomy device 125 with an undersized initial gap (G₀), so that anideal gap (G_(i)) may be gradually achieved via non-invasiveadjustments. It is contemplated that over the adjustment period, a totalof one to twenty or more adjustment procedures may be performed, for atotal amount of about 1 mm to about 20 mm of gap (G) increase, such asduring an adjustment period of one month or less. Typically, theadjustment period may span approximately ten days, involve approximatelyten adjustment procedures and involve a total amount of about 5 mm toabout 12 mm gap increase.

By locating the non-invasively adjustable wedge osteotomy device 125medially in the tibia, instead of near the centerline, a larger momentmay be placed on the first portion 119 and second portion 121 to openthe open wedge osteotomy 118 in relation to the hinge point 107.Additionally, for any particular distraction force applied by thenon-invasively adjustable wedge osteotomy device 125, a larger amount ofdistraction may be achieved. In FIG. 28, three different distractionaxes (A, B, C) are shown, representing three possible positions of thenon-invasively adjustable wedge osteotomy device 125. Distraction axis Ais approximately midline in the tibia 102, while distraction axis B isapproximately 11° angled from the midline, and distraction axis C isapproximately 22° angled from the midline. The length D_(B) from thehinge point 107 to distraction axis B can be approximately 32% greaterthan the length D_(A) from the hinge point 107 to distraction axis A.More significantly, the length D_(C) from the hinge point 107 todistraction axis C can be approximately 60% greater than the lengthD_(A) from the hinge point 107 to distraction axis A. The distractionforce of the non-invasively adjustable wedge osteotomy device 125 isneeded to overcome a series of resistances arrayed along the tibia dueto the tethering effect of soft tissue. A placement of thenon-invasively adjustable wedge osteotomy device 125 along axis C, andthus in second cavity 115 (FIG. 27), can allow for a more effectivedistraction of the open wedge osteotomy 118.

FIGS. 29 through 31 illustrate a method of implanting and operating anon-invasively adjustable wedge osteotomy device 125 for changing anangle of the tibia of a patient, but unlike the open wedge osteotomy 118shown in FIGS. 20-27, a closing wedge osteotomy 141 is shown. In FIG.29, the first cut 103 is made, but in FIG. 30 a second cut 105 is madeand a wedge of bone is removed. The second cut 105 purposely removesslightly more bone than is needed to optimize the correction angle, andas shown in FIG. 31, the closing wedge osteotomy 141 is left with aslight gap, allowing it to be subsequently adjusted in either direction(to increase or decrease then angle). The implantation method continuesby following the remaining steps described in FIGS. 22-26, and the angleof the closing wedge osteotomy 141 may be increased or decreased asdescribed in FIG. 27.

FIGS. 32 through 36 illustrate a first system for excavation of bonematerial 400. The system for excavation of bone material 400 isconfigured for creating a second cavity 115 as generally described inFIGS. 22 through 24. A drive unit 404 is coupled to a rotational cuttingtool 402 by means of a flexible drive train 408. The rotational cuttingtool 402 is an embodiment of the excavation device 113 as introduced inFIG. 23, but may also serve as the drill 111 of FIG. 22. The rotationalcutting tool 402, as depicted in FIGS. 32 through 35, extends between afirst end 444 and second end 446 (as shown in FIG. 34), and comprises adistal reamer 412 which is coupled to a proximal reamer 410. As shown inFIG. 35, the distal reamer 412 includes a small diameter portion 440which inserts inside the proximal reamer 410. A circumferentialengagement member 434 is held axially between the distal reamer 412 andthe proximal reamer 410, and includes several cutouts 435 (FIG. 34)arrayed around its circumference, forming a pulley. The distal reamer412, proximal reamer 410 and circumferential engagement member 434 areheld together with pins 437, which are passed through holes 436, andwhich assure that all components rotate in unison. A cap screw 438 issecured within a female threaded internal surface of the proximal reamer410. The distal reamer 412 further includes a taper 442 and a blunt tip414. The outer diameter of the rotational cutting tool 402 may be about12 mm or less, and more specifically about 10 mm or less. The outerdiameter of the proximal reamer 410 may be about 9 mm and the outerdiameter of the distal reamer may taper from about 9 mm to about 6.35 mmat the blunt tip 414. The drive unit 404, as best seen in FIGS. 32 and36, comprises a drive housing 416 covered by a pulley cover plate 418and a drive cover plate 420. Several screws 421 hold the drive coverplate 420 to the drive housing 416, and four screws 426 hold the pulleycover plate 418 to the drive housing 416. The drive housing 416 is notdepicted in FIG. 36 in order to reveal more detail of the internalcomponents. In FIG. 32, a handle 406 is coupled by screws 424 to ahandle mounting plate 422 which in turn is removably attached to thedrive housing 416 (for example by screws or a clip).

A shaft 428 (FIG. 36) having a keyed end 430, is configured forremoveably coupling to an electric drill unit 468 (FIGS. 37 and 38). Alarge pulley 450 is attached to the shaft 428 with a set screw 451 sothat rotation of the shaft 428 by the electric drill unit 468 causesrotation of the large pulley 450. The shaft 428 and large pulley 450 areheld between two ball bearings 448 (lower ball bearing not visible), anda shim washer 464 and wave washer 466 are located on either side of thelarge pulley 450 in order to control the amount of axial play. A rollerwheel 452 is rotatably attached to the end of a roller wheel slide 456with a pin 454. The roller wheel slide 456 is able to slide axiallywithin the drive housing 416 and drive cover plate 420 with theloosening of a thumb screw 432, whose threaded shaft engages withinternal threads 462 on the roller wheel slide 456. The roller wheelslide 456 may be secured by tightening the thumb screw 432 so that itwill not slide during use. A longitudinal slit 460 in the roller wheelslide 456 controls the total amount of axial sliding by providing afirst end 461 and a second end 463 which abut a stop 458.

The flexible drive train 408 comprises a small timing belt, for examplean about 3 mm wide Kevlar® or fiberglass reinforced polyurethane belthaving a slippage torque of greater than 10 inch-ounces when used withthe large pulley 450 or the circumferential engagement member 434. Onepotential example slippage torque for is 13 inch-ounces. The teeth ofthe flexible drive train may be located at a pitch of two millimeters.FIG. 37 shows the drive unit 404 of the System for excavation of bonematerial 400 coupled to the electric drill unit 468. The electric drillunit 468 includes a motor housing 476, a handle 470 and a battery pack472. The handle may include any number of interfaces known in the artfor turning the electric drill unit 468 on or off, or controlling thespeed. In some embodiments, the electric drill unit 468 may plugdirectly into a standard power source instead of having the battery pack472. The keyed end 430 of the shaft 428 is coupled to a shaft coupler474 of the electric drill unit 468.

In FIG. 37, the first cavity 109 having been created, the flexible drivetrain 408 is inserted through the medial incision and into the openwedge osteotomy 118, between first portion 119 and second portion 121 ofthe tibia. The rotational cutting tool 402 is then placed down the firstcavity 109 of the tibia 102 so that the flexible drive train 408 wrapsaround the circumferential engagement member 434 of the rotationalcutting tool 402. With the thumb screw 432 loose, the desired amount oftension in the flexible drive train 408 is adjusted and then the thumbscrew 432 is tightened. At this desired tension, the teeth of theflexible drive train 408 should engage well within the cutouts 435 (FIG.34) of the circumferential engagement member 434 and the roller wheel452 should rotatably contact the outer surface of the circumferentialengagement member 434, stabilizing it. The electric drill unit 468 isoperated, causing the large pulley 450 of FIG. 36 to rotate the flexibledrive train 408, and thus rotate the rotational cutting tool 402 viaengagement with the circumferential engagement member 434 (FIG. 34). Thelarge pulley 450 can be twice the diameter of the circumferentialengagement member 434, therefore causing the rotational cutting tool 402to spin at one-half the speed of the output of the electric drill unit468. Other ratios are also within the scope of this invention. It may bedesired to control the rotational speed of the rotational cutting tool402 in order to minimize heating of the bone surrounding the bonematerial being cut, and thus limit damage to the bone that may impedenormal growth during the healing process. While the rotational cuttingtool 402 is rotated by the drive unit 404, The handle 406 is pulledcausing the rotational cutting tool 402 to cut a second cavity 115following path 477 (FIG. 38). The proximal reamer 410 cuts within firstportion 119 of the tibia 102 and the distal reamer 412 cuts within thesecond portion 121 of the tibia 102. After the second cavity 115 iscreated, the thumb screw 432 is loosened and tension on the flexibledrive train 408 is at least partially reduced. The rotational cuttingtool 402 is then removed and the flexible drive train 408 is pulled outof the open wedge osteotomy 118. A tether line may be attached to therotational cutting tool 402, for example via the cap screw 438, to applytension and thus aid removal. A swivel joint may further be includedbetween the tether line and the rotational cutting tool 408 in order tokeep the tether line from being twisted.

FIG. 39-41 illustrate a second system for excavation of bone material500. The system for excavation of bone material comprises an excavationdevice 502 having a hollow outer shaft 508. The hollow outer shaft 508has a distal end 507 and a proximal end 509 and is attached to an outershaft handle 510 which is configured to be held with a single hand tostabilize or to move the excavation device 502. An adjustment member 512having a threaded end 516 is attached to an adjustment handle 514. Thethreaded end 516 threadingly engages internal threads (not shown) withinthe hollow outer shaft 508, and turning the adjustment member 512 bymanipulation of the adjustment handle 514 moves the adjustment member512 axially in relation to the hollow outer shaft 508. The hollow outershaft 508 has a cut away section 511 adjacent to an articulatable arm504. The threaded end 516 is coupled to the arm 504 via a link 520. Thelink 520 connects to the arm 504 at a first pivot point 518, and thelink 520 connects to the threaded end 516 of the adjustment member 512at a second pivot point 521 (as seen in FIG. 40). Rotating theadjustment handle 514 in a rotational direction R in relation to thehollow outer shaft 508 and outer shaft handle 510 causes adjustmentmember 512 to move in direction D in relation to the hollow outer shaft508, and causes the arm 504 to expand in path E in relation to thehollow outer shaft 508.

The arm 504 comprises an abrading surface 506 for removing bonematerial. As seen in FIG. 41, the arm 504 may be an elongate memberhaving a semi-cylindrical cross-section, and the abrading surface 506may comprise a rasp, covered with several sharp projections 513. FIG. 39shows the excavation device 502 placed within a first cavity 109 madewithin a tibia 102. In order to create a second cavity 115 to one sideof the first cavity 109, the operator grips the outer shaft handle 510with one hand and the adjustment handle 514 with the other hand, andbegins moving the system for excavation of bone material 500 in a backand forth motion 522, while slowly turning the adjustment handle 514 inrotational direction R. As bone material is removed, the arm 504 is ableto be expanded more and more along path E (FIG. 40) as the adjustmenthandle 514 is turned in rotational direction R and the system forexcavation of bone material 500 is moved in a back and forth motion 522.The culmination of this step is seen in FIG. 40, with the second cavity115 created in the first portion 119 and the second portion 121 of thetibia 102. At the completion of this step, the adjustment handle isturned in an opposite rotational direction than rotational direction R,thus allowing the arm 504 to collapse, and the excavation device 502 tobe removed from the tibia 102.

FIG. 42-44 illustrate a third system for excavation of bone material600. The system for excavation of bone material 600 comprises anexcavation device 602 having a hollow outer shaft 608. The hollow outershaft 608 has a distal end 607 and a proximal end 609 and is attached toan outer shaft handle 610 which is configured to be held with a singlehand to stabilize or to move the excavation device 602. An adjustmentmember 612 having a threaded end 616 is attached to an adjustment handle614. The threaded end 616 threadingly engages internal threads (notshown) within the hollow outer shaft 608, and turning the adjustmentmember 612 by manipulation of the adjustment handle 614 moves theadjustment member 612 axially in relation to the hollow outer shaft 608.The hollow outer shaft 608 has a cut away section 611 adjacent to anarticulatable arm 604. The threaded end 616 is coupled to the arm 604via a link 620. The link 620 connects to the arm 604 at a first pivotpoint 618, and the link 620 connects to the threaded end 616 of theadjustment member 612 at a second pivot point 621. Rotating theadjustment handle 614 in a rotational direction R in relation to thehollow outer shaft 608 and outer shaft handle 610 causes adjustmentmember 612 to move in direction D in relation to the hollow outer shaft608, and causes the arm 604 to expand in path E in relation to thehollow outer shaft 608, as seen in FIG. 43.

As seen in FIG. 44, the arm 604 comprises a compaction surface 606 forcompacting cancellous bone. The arm 604 may be an elongate member havinga tubular or partially tubular cross-section, and the compaction surface606 may include a leading edge 690 for cutting a path through thecancellous bone and a first angled surface 692 extending from theleading edge 690. The first angled surface 692 serves to compact thecancellous bone, but also allows some sliding past cancellous bone asthe cancellous bone moves out of the way. Similarly, a second angledsurface 694 having an angle different from that of the first angledsurface 692 may be configured as part of the compaction surface 606.FIG. 42 shows the excavation device 602 placed within a first cavity 109made within a tibia 102. In order to create a second cavity 115 to oneside of the first cavity 109, the operator grips the outer shaft handle610 with one hand and the adjustment handle 614 with the other hand, andbegins slowly turning the adjustment handle 614 in rotational directionR. Cancellous bone is compacted as the arm 604 is expanded more and morealong path E by turning the adjustment handle 614 in rotationaldirection R. The culmination of this step is seen in FIG. 43, with thesecond cavity 115 created in the second portion 121 of the tibia 102.The excavation device 602 may be moved superiorly in the tibia 102 andthe compaction may be completed within the first portion 119 of thetibia 102. At the completion of the compaction step, the adjustmenthandle is turned in an opposite rotational direction than rotationaldirection R, thus allowing the arm 604 to collapse, and the excavationdevice 602 to be removed from the tibia 102.

FIGS. 45A through 50 illustrate a non-invasively adjustable wedgeosteotomy device 700. The non-invasively adjustable wedge osteotomydevice 700 has a first end 726 and a second end 728, as shown in FIG.45A, and is similar in construction to the non-invasively adjustablewedge osteotomy device 300 of FIGS. 17 through 19. However, the firstend 726 of the non-invasively adjustable wedge osteotomy device 700comprises a Herzog bend 780, in which the first end 726 projects at anangle θ. In some embodiments, the angle θ may range between about 5° andabout 20°, or more specifically between about 8° to 12°, or about 10°,in relation to the central axis 782 of the non-invasively adjustablewedge osteotomy device 700. A magnetically adjustable actuator 742comprises an inner shaft 732, telescopically disposed within an outerhousing 730, the outer housing 730 further comprising a distractionhousing 712 and a gear housing 706. First transverse hole 735, secondtransverse hole 743, third transverse hole 737 and fourth transversehole 739 are sized for the passage of bone anchors, for example lockingscrews having diameters of about 3.0 mm to about 5.5 mm, and morespecifically about 4.0 mm to about 5.0 mm. In some embodiments, thediameter of the outer housing 730 is between about 7.0 mm and about 9.5mm, and more specifically about 8.5 mm. The diameter of the inner shaft732 may also taper up to about 8.5 mm at the portion of the inner shaft732 containing the second transverse hole 743 and third transverse hole737. This is larger than the small-diameter portion 784 of the innershaft 732, which telescopes within the outer housing 730, and thus thisincrease diameter allows the second transverse hole 743 and thirdtransverse hole 737 to in turn be constructed with larger diameters,allowing the use of stronger, larger diameter bone screws. Likewise, thediameter of the first end 726 may taper up to about 10.7 mm in order toallow for even larger bone screws to be used. In a non-invasivelyadjustable wedge osteotomy device 700 having an outer housing 730diameter of about 8.5 mm, tapering up to about 10.7 mm at the first end726, and with an inner shaft 732 that tapers up to about 8.5 mm, it iscontemplated that bone screws having diameter of about 4.0 mm will beplaced through the second transverse hole 743 and the third transversehole 737, while bone screws having a diameter of about 5.0 mm will beplaced through the first transverse hole 735 and the fourth transversehole 739. An exemplary length of the non-invasively adjustable wedgeosteotomy device 700 from the extents of the first end 726 to the secondend 728 is about 150 mm.

As seen in more detail in FIG. 46, an interface 766 at the first end 726of the non-invasively adjustable wedge osteotomy device 700 includesinternal thread 797 for reversible engagement with the male threads ofan insertion tool. Examples of methods and embodiments of instrumentsthat may be used to implant the non-invasively adjustable wedgeosteotomy device 700, or other embodiments of the present invention, aredescribed in U.S. Pat. No. 8,449,543, the disclosure of which is herebyincorporated by reference in its entirety. The fourth transverse hole739 comprises a dynamic construction that allows some motion between abone anchor and the non-invasively adjustable wedge osteotomy device 700when the non-invasively adjustable wedge osteotomy device 700 isimplanted and being non-invasively adjusted. A bushing 751, havingsubstantially cylindrical outer and inner diameters resides within thefourth transverse hole 739 and has an inner diameter 753 configured tosmoothly pass the shaft of a locking screw, for example a locking screwhaving a diameter of about 5.0 mm. In some embodiments, the bushing 751may be constructed of metallic materials such as Titanium-6Al-4V. Inother embodiments the bushing 751 may be constructed of PEEK. Thebushing 751 can be angularly unconstrained, thus being able to rock orpivot within the fourth transverse hole 739.

FIG. 47 shows the non-invasively adjustable wedge osteotomy device 700in a first, non-distracted state. The inner shaft 732 is substantiallyretracted within the outer housing 730. FIG. 48 shows the non-invasivelyadjustable wedge osteotomy device 700 in a partially distracted state,with a portion of the inner shaft 732 extending from the outer housing730 (for example, after having been magnetically distracted). Inaddition, FIGS. 47 and 48 show two different possible positions for abone screw 755, having a head 757, a shaft 759 and a threaded portion761 for engaging cortical bone. The bone screw 755 is depicted rockingor pivoting along a general arcuate pathway 763. The bushing 751 maygenerally rock within the fourth transverse hole 739, or the bushing 751may actually pivot upon an axis. For example, pins may extendtransversely from the outer diameter of the bushing 751 at approximatelythe center point of its length, and attach into holes or recesses formedtransversely within the fourth transverse hole 739. The words “rock” and“rocking”, as used herein, are generally intended to denote a motionthat does not have a central pivot point. “Angularly unconstrained,” asused herein, is intended to denote any freedom of motion of the bushing751 that allows angulation, not necessarily in a single plane, of thebone screw 755 in relation to the non-invasively adjustable wedgeosteotomy device 700. “Angularly unconstrained,” as used herein, isintended to include both rocking and pivoting.

FIGS. 49 and 50 illustrate sectional views of the bushing 751 moving inan angularly constrained manner within the fourth transverse hole 739.As seen in FIG. 51, bushing 751 comprises two large diameter extensions765, 770 and two small diameter extensions 767, 768, separated by atransition area 769. In some embodiments, a longitudinal slit 771 alongone side of the bushing 751 may be present, to allow bone screws 755having a certain amount of outer diameter variance to fit within theinner diameter 753. In FIG. 49, the bushing 751 has not reached itsextents against the fourth transverse hole 739. In contrast, FIG. 50shows one large diameter extension 765 abutting a first point 773 withinthe fourth transverse hole 739, and the other large diameter extension770 abutting a second point 775 within the fourth transverse hole 739.In addition, this longitudinal slit 771, or alternatively, externalcontours on the bushing 751, may fit within matching contours the fourthtransverse hole 739, so that the bushing 751 cannot rotate around itscylindrical axis (in relation to the fourth transverse hole 739), but isstill able to rock or pivot. The sizing of the two large diameterextensions 765, 770 and two small diameter extensions 767, 768 may becontrolled, for example, so that the bushing 751 is able to rock orpivot about 15° in one direction, but about 0° in the other direction.These about 15°, for example, may be chosen to correspond to the totalamount of opening of the open wedge osteotomy 118 in a particularpatient. The extent of this angulation may be controlled in differentmodels of the bushing 751. For example about 15° in one direction, about0° in the other direction; about 10° in one direction, about 5° in theother direction; about 20° in one direction, about 0° in the otherdirection; and about 10° in one direction, about 10° in the otherdirection.

FIGS. 52-55 illustrate a method of implanting and operating thenon-invasively adjustable wedge osteotomy device 700 of FIGS. 45A-51 formaintaining or adjusting an angle of an opening wedge osteotomy of thetibia of a patient. In FIG. 52, a first cavity 109, extending from afirst point on the tibia 102 at the tibial plateau 101, is made. In someembodiments, the first cavity 109 can be made as shown in FIGS. 20-22.In FIG. 53, the non-invasively adjustable wedge osteotomy device 700 isinserted into the first cavity 109, the inner shaft 732 first, followedby the outer housing 730. In FIG. 54, the non-invasively adjustablewedge osteotomy device 700 is secured to the first portion 119 of thetibia 102 with a first bone screw 755 which is passed through the fourthtransverse hole 739 of FIG. 45B, and a second bone screw 777 which ispassed through the first transverse hole 735, of FIG. 45B. In thisembodiment, only the fourth transverse hole 739 has the bushing 751incorporated therein. A third bone screw 779 and a fourth bone screw 781are passed through the second transverse hole 743, in FIG. 45B, and thethird transverse hole 737, in FIG. 45B, respectively, and secured to thesecond portion 121 of the tibia 102. The non-invasively adjustable wedgeosteotomy device 700 is secured within the tibia 102 so that the Herzogbend 780, of FIG. 45A, points anteriorly (e.g. towards the patellartendon). FIG. 55 illustrates the non-invasively adjustable wedgeosteotomy device 700 after having been distracted over one or morenon-invasive distractions, over a period of one or more days. The angleof the open wedge osteotomy 118 has been increased as the inner shaft732 was displaced out of the outer housing 730. The bone screw 755 hasbeen able to change its angle in relation to the non-invasivelyadjustable wedge osteotomy device 700, for example, by rocking orpivoting of the bushing 751 of FIG. 49 within the fourth transverse hole739.

FIGS. 56A through 56D illustrate four possible bone screw configurationsfor securing the first end 726 of the non-invasively adjustable wedgeosteotomy device 700 to the first portion 119 of the tibia 102 with thefirst bone screw 755 and the second bone screw 777. The medial 800,lateral 802, anterior 804 and posterior 806 portions of the tibia 102are denoted. The medial 800 to lateral 802 orientation in FIGS. 56Athrough 56D is left to right respectively in each figure, while in FIGS.52 through 55, medial was on the right and lateral was on the left. Inthe configuration of FIG. 56A, the first bone screw 755 is securedunicortically (through the cortex of the tibia 102 on one side only) andis at an angle of B≈10° with the medial-lateral axis 810. The secondbone screw 777 is secured bicortically (through the cortex of the tibia102 on both sides) and is at an angle of A≈20° with theanterior-posterior axis 808. In the configuration of FIG. 56B, the firstbone screw 755 is secured unicortically and is at an angle of B≈10° (inthe opposite direction than in FIG. 56A) with the medial-lateral axis810. The second bone screw 777 is secured bicortically and is at anangle of A≈20° with the anterior-posterior axis 808. In theconfiguration of FIG. 56C, the first bone screw 755 and the second bonescrew 777 are both secured bicortically. First bone screw 755 is securedat an angle of D≈45° with the anterior-posterior axis 808, and secondbone screw 777 is secured at an angle of A≈20° with theanterior-posterior axis 808. In the configuration of FIG. 56D, the firstbone screw 755 and the second bone screw 777 are both securedbicortically. First bone screw 755 is secured at an angle of D≈45° withthe anterior-posterior axis 808, and second bone screw 777 is secured atan angle of E≈45° with the anterior-posterior axis 808.

Though not shown in FIGS. 56A through 56D, the third bone screw 779 andthe fourth bone screw 781 may be secured in a number of orientations.Though shown in FIGS. 54 and 55 oriented slightly angled from theanterior-posterior plane, they may also be placed in other orientations,for example angled approximately 35° from the medial-lateral plane.

FIG. 57 illustrates a non-invasively adjustable wedge osteotomy device900. The non-invasively adjustable wedge osteotomy device 900 comprisesa magnetically adjustable actuator 942 having a first end 926 and asecond end 928, and is similar in construction to the non-invasivelyadjustable wedge osteotomy device 300 of FIGS. 17 through 19. The secondend 928 includes an inner shaft 932 having a small-diameter portion 984which is telescopically disposed and axially distractable within anouter housing 930. The outer housing 930 comprises a distraction housing912 and a gear housing 906. A first plate 950 extends from the outerhousing 930 and is configured to be placed in proximity to an externalsurface of a bone, for example, the second portion 121 of a tibia 102shown in FIG. 59. One or more anchor holes 952 are arrayed on the firstplate 950, and configured for interface with corresponding bone screws.A bone screw 954 is shown in FIG. 58, and includes a threaded, taperedhead 956 and a threaded shaft 958. A keyed cavity 960 couples with adriving instrument (not shown). The first plate 950 features a boneinterface side 962 and a non-bone interface side 964. A second plate966, having a bone interface side 968 and a non-bone interface side 970,extends from the inner shaft 932. The second plate 966 is coupled to theinner shaft 932 by a cap 972, and secured with a set screw 974. One ormore anchor holes 976 are arrayed on the second plate 966, andconfigured for interface with corresponding bone screws, for examplebone screw 954. Anchor hole 978 is shown having a threaded taper 980,for interfacing with the tapered head 956 of the bone screw 954.

FIGS. 59-61 illustrate a method of implanting and operating thenon-invasively adjustable wedge osteotomy device of FIG. 57 formaintaining or adjusting an angle of an opening wedge osteotomy of thetibia of a patient. In FIG. 59, an open wedge osteotomy 118 is made inthe tibia 102. In FIG. 60, the non-invasively adjustable wedge osteotomydevice 900 is placed through an incision and is secured to the tibia 102by coupling the first plate 950 to the second portion 121 of the tibia102 and coupling the second plate 966 to the first portion 119 of thetibia, for example with bone screws 954. FIG. 61 illustrates the tibia102 after the non-invasively adjustable wedge osteotomy device 900 hasbeen non-invasively distracted, for example with the external adjustmentdevice 1180.

FIGS. 62 and 63 illustrate a non-invasively adjustable wedge osteotomydevice 1000. The non-invasively adjustable wedge osteotomy device 1000comprises a magnetically adjustable actuator 1042 having a first end1026 and a second end 1028, and is similar in construction to thenon-invasively adjustable wedge osteotomy device 300 of FIGS. 17 through19, and the non-invasively adjustable wedge osteotomy device 900 of FIG.57. The magnetically adjustable actuator 1042 comprises an outer housing1030 and an inner shaft 1032 telescopically disposed within the outerhousing 1030. Like the non-invasively adjustable wedge osteotomy device900 of FIG. 57, non-invasively adjustable wedge osteotomy device 1000has a first plate 1050 extending from the outer housing 1030. A secondplate 1066 is secured to the inner shaft 1032 by a cap 1072. The secondplate 1066 is rotatably coupled to the cap 1072 at pivot point 1091,thus allowing the second plate 1066 to rotate from the position in FIG.62 to the position in FIG. 63 along arrow 1081, for example as the innershaft 1032 is distracted from the position in FIG. 62 to the position inFIG. 63. This allows the first portion 119 of the tibia 102 to be movedapart from the second portion 121 of the tibia 102, and thus opening theopen wedge osteotomy 118, but without creating too large of a bendingmoment (and related frictional force increases) on the movement of theinner shaft 1032 within the outer housing 1030. In this manner, thetorque supplied by the magnetic coupling of the external adjustmentdevice 1180 of FIG. 15 will be sufficient to distract the magneticallyadjustable actuator 1042. The rotatability of the second plate 1066 withrelation to the rest of the non-invasively adjustable wedge osteotomydevice 900 is analogous to the angularly unconstrained motion of thebushing 751 and the bone screw 755 in relation to the non-invasivelyadjustable wedge osteotomy device 700 of FIGS. 45A through 50.

The use of the non-invasively adjustable wedge osteotomy device 900 orthe non-invasively adjustable wedge osteotomy device 1000, which do notrequire any removal of bone at the tibial plateau 101, may be preferredin certain patients in whom it is desired to maintain the knee joint 104in as original a condition as possible. This may include youngerpatients, patients who may be able to avoid later partial or total kneereplacement, or patients with deformities at the knee joint 104. It mayalso include small patients who have small medullary canal dimensions,in whom intramedullary devices will not fit well.

FIGS. 64A through 64C illustrate a magnetically adjustable actuator 1504which may be used with any of the embodiments of the present invention,and which allows for temporary or permanent removal of a rotatablemagnetic assembly 1542. Subjects undergoing magnetic resonance imaging(MRI) may require that the radially-poled permanent magnet 1502 beremoved prior to MRI in order to avoid an imaging artifact which may becaused by the radially-poled permanent magnet 1502. Additionally, thereis a risk that an implanted radially-poled permanent magnet 1502 may bedemagnetized upon entering an MRI scanner. In some embodiments, anactuator housing cap 1588 has a male thread 1599 which engages with afemale thread 1597 of the outer housing 1505 of the magneticallyadjustable actuator 1504. In other embodiments, a snap/unsnap interfacemay be used. A smooth diameter portion 1595 of the actuator housing cap1588 is sealed within an o-ring 1593, which is held within acircumferential groove in the outer housing 1505. If at a timesubsequent to the implantation of the magnetically adjustable actuator1504 it desired to remove the rotatable magnetic assembly 1542 whileleaving the rest of the implant intact, a small incision may be made inthe skin of the subject in proximity to the actuator housing cap 1588,and the actuator housing cap 1588 may be unscrewed. The rotatablemagnetic assembly 1542 may then be removed, as shown in FIG. 64A. FIGS.64B and 64C show the subsequent steps of replacing the actuator housingcap 1588 onto the magnetically adjustable actuator 1504, once againsealing it with the o-ring 1593. The incision may then be closed, andthe subject can undergo typical MRI scanning. If desired, after the MRIscanning, the magnetic assembly 1542 may be replaced by following areverse method.

FIGS. 65A through 65D illustrate a magnetically adjustable actuator 1604which may be used with any of the embodiments of the present invention,and which advantageously allows for temporary or permanent removal ofthe radially-poled permanent magnet 1602. An actuator housing cap 1688attaches to and detaches from the magnetically adjustable actuator 1604in the same manner as in the magnetically adjustable actuator 1504 ofFIGS. 64A through 64C. The radially-poled permanent magnet 1602 has tworadial portions 1687 and two flat portions 1685. The two flat portions1685 fit within flat walls 1683 of a magnetic housing 1640, which allowsrotation of the radially-poled permanent magnet 1602 to directly imparta torque upon the magnetic housing 1640 without the need for anyadhesive or epoxy. A magnetic housing cap 1681 having an o-ring 1679 isattachable to and removable from the magnetic housing 1640. If an MRI ofthe subject is desired and it has been determined that theradially-poled permanent magnet 1602 should be removed, an smallincision is made in the skin of the subject in proximity to the actuatorhousing cap 1688, and the actuator housing cap 1688 is removed. Thenmagnetic housing cap 1681 is removed from the magnetic housing 1640. Apull rod 1677 extends through a longitudinal hole (not shown) in theradially-poled permanent magnet 1602, extending at one end such that itmay be gripped, for example by forceps or hemostats. The pull rod 1677may have a flat base 1675 at the opposite end so that when it is pulled,it can drag the radially-poled permanent magnet 1602 with it. Theradially-poled permanent magnet 1602 can be permanently or temporarilyremoved (FIG. 65B) (note removal path 1691) and the magnetic housing cap1681 replaced (FIG. 65C). The actuator housing cap 1688 can then bereplaced (FIG. 65D). The incision is then closed, and the subject mayundergo typical MRI scanning. If desired, after the MRI scanning, theradially-poled permanent magnet 1602 may be replaced by following areverse method. Alternatively, the magnetic housing cap 1681 or theactuator housing cap 1688 may be replaced by an alternatively shaped capwhich will guide into a keyed structure within the magnet actuator 1604,thus keeping the internal mechanisms from turning, and keeping thesubject's particular amount of adjustment from changing as he subjectwalks, runs or stretches.

Throughout the embodiments presented, a radially-poled permanent magnet(e.g. 168 of FIG. 8), as part of a magnetic assembly (e.g. 166), is useda driving element to remotely create movement in a non-invasivelyadjustable wedge osteotomy device. FIGS. 66-69 schematically show fouralternate embodiments, wherein other types of energy transfer are usedin place of permanent magnets.

FIG. 66 illustrates a non-invasively adjustable wedge osteotomy device1300 comprising an implant 1306 having a first implant portion 1302 anda second implant portion 1304, the second implant portion 1304non-invasively displaceable with relation to the first implant portion1302. The first implant portion 1302 is secured to a first bone portion197 and the second implant portion 1304 is secured to a second boneportion 199 within a patient 191. A motor 1308 is operable to cause thefirst implant portion 1302 and the second implant portion 1304 todisplace relative to one another. An external adjustment device 1310 hasa control panel 1312 for input by an operator, a display 1314 and atransmitter 1316. The transmitter 1316 sends a control signal 1318through the skin 195 of the patient 191 to an implanted receiver 1320.Implanted receiver 1320 communicates with the motor 1308 via a conductor1322. The motor 1308 may be powered by an implantable battery, or may bepowered or charged by inductive coupling.

FIG. 67 illustrates a non-invasively adjustable wedge osteotomy device1400 comprising an implant 1406 having a first implant portion 1402 anda second implant portion 1404, the second implant portion 1404non-invasively displaceable with relation to the first implant portion1402. The first implant portion 1402 is secured to a first bone portion197 and the second implant portion 1404 is secured to a second boneportion 199 within a patient 191. An ultrasonic motor 1408 is operableto cause the first implant portion 1402 and the second implant portion1404 to displace relative to one another. An external adjustment device1410 has a control panel 1412 for input by an operator, a display 1414and an ultrasonic transducer 1416, which is coupled to the skin 195 ofthe patient 191. The ultrasonic transducer 1416 produces ultrasonicwaves 1418 which pass through the skin 195 of the patient 191 andoperate the ultrasonic motor 1408.

FIG. 68 illustrates a non-invasively adjustable wedge osteotomy device1700 comprising an implant 1706 having a first implant portion 1702 anda second implant portion 1704, the second implant portion 1704non-invasively displaceable with relation to the first implant portion1702. The first implant portion 1702 is secured to a first bone portion197 and the second implant portion 1704 is secured to a second boneportion 199 within a patient 191. A shape memory actuator 1708 isoperable to cause the first implant portion 1702 and the second implantportion 1704 to displace relative to one another. An external adjustmentdevice 1710 has a control panel 1712 for input by an operator, a display1714 and a transmitter 1716. The transmitter 1716 sends a control signal1718 through the skin 195 of the patient 191 to an implanted receiver1720. Implanted receiver 1720 communicates with the shape memoryactuator 1708 via a conductor 1722. The shape memory actuator 1708 maybe powered by an implantable battery, or may be powered or charged byinductive coupling.

FIG. 69 illustrates a non-invasively adjustable wedge osteotomy device1800 comprising an implant 1806 having a first implant portion 1802 anda second implant portion 1804, the second implant portion 1804non-invasively displaceable with relation to the first implant portion1802. The first implant portion 1802 is secured to a first bone portion197 and the second implant portion 1804 is secured to a second boneportion 199 within a patient 191. A hydraulic pump 1808 is operable tocause the first implant portion 1802 and the second implant portion 1804to displace relative to one another. An external adjustment device 1810has a control panel 1812 for input by an operator, a display 1814 and atransmitter 1816. The transmitter 1816 sends a control signal 1818through the skin 195 of the patient 191 to an implanted receiver 1820.Implanted receiver 1820 communicates with the hydraulic pump 1808 via aconductor 1822. The hydraulic pump 1808 may be powered by an implantablebattery, or may be powered or charged by inductive coupling. Thehydraulic pump 1808 may alternatively be replaced by a pneumatic pump.

In one embodiment a system for changing an angle of a bone of a subjectincludes an adjustable actuator having an outer housing and an innershaft, telescopically disposed in the outer housing; a magnetic assemblyconfigured to adjust the length of the adjustable actuator though axialmovement of the inner shaft and outer housing in relation to oneanother; a first bracket configured for coupling to the outer housing; asecond bracket configured for coupling to the inner shaft; and whereinapplication of a moving magnetic field externally to the subject movesthe magnetic assembly such that the inner shaft and the outer housingmove in relation to one another.

In another embodiment, a system for changing an angle of a bone of asubject includes a magnetic assembly comprising a radially-poled magnetcoupled to a shaft having external threads; a block having internalthreads and coupled to the shaft, wherein rotational movement of theradially-poled magnet causes the shaft to turn and to move axially inrelation to the block; an upper bone interface and a lower boneinterface having an adjustable distance; and wherein axial movement ofthe shaft in a first direction causes the distance to increase. Theupper and lower bone interfaces may be formed as part of a plate spring.The upper and lower bone interfaces may be formed as part of a pluralityof interlinked plates.

In another embodiment, a system for changing an angle of a bone of asubject includes a scissors assembly comprising first and second scissorarms pivotably coupled via a hinge, the first and second scissor armscoupled, respectively, to upper and lower bone interfaces configured tomove relative to one another; a hollow magnetic assembly containing anaxially moveable lead screw disposed therein, wherein the hollowmagnetic assembly is configured to rotate in response to a movingmagnetic field and wherein said rotation translations into axialmovement of the lead screw; a ratchet assembly coupled at one end to thelead screw and at another end to one of the first and second scissorarms, the ratchet assembly comprising a pawl configured to engage teethdisposed in one of the upper and lower bone interfaces; and whereinaxial movement of the lead screw advances the pawl along the teeth andmoves the upper and lower bone interfaces away from one another

In another embodiment, a method of preparing a tibia for implantation ofan offset implant includes making a first incision in the skin of apatient at a location adjacent the tibial plateau of the tibia of thepatient; creating a first cavity in the tibia by removing bone materialalong a first axis extending in a substantially longitudinal directionfrom a first point at the tibial plateau to a second point; placing anexcavation device within the first cavity, the excavation deviceincluding a main elongate body and configured to excavate the tibiaasymmetrically in relation to the first axis; creating a second cavityin the tibia with the excavation device, wherein the second cavitycommunicates with the first cavity and extends substantially towards oneside of the tibia; and removing the excavation device. The second cavitymay extend substantially laterally in the patient. The second cavity mayextend substantially medially in the patient. The method may furtherinclude compacting a portion of the cancellous bone of the tibia in thecreating a second cavity step. The excavation device may comprise anarticulating arm having a first end and a second end, the arm includinga compaction surface. The compaction surface may include a leading edgeand at least one angled surface. The arm may be adjustable in relationto the main elongate body. The first end of the arm may be pivotallycoupled to the main elongate body and the second end of the arm may beadjustable to a plurality of distances from the main elongate body. Theexcavation device may be coupled to an adjustment member configured tomove the second end of the arm into at least one of the plurality ofdistances from the main elongate body. The creating a second cavity stepmay further comprise adjusting the adjustment member to move the secondend of the arm along at least several of the plurality of distances fromthe main elongate body such that the compaction surface compactscancellous bone against cortical bone. The creating a second cavity stepmay comprise removing bone material from the tibia. The excavationdevice may comprise an articulating arm having a first end and a secondend, the arm including an abrading surface. The abrading surface maycomprise a rasp. The arm may be adjustable in relation to the mainelongate body. The first end of the arm may be pivotally coupled to themain elongate body and the second end of the arm may be adjustable to aplurality of distances from the main elongate body. The excavationdevice may be coupled to an adjustment member configured to move thesecond end of the arm into at least one of the plurality of distancesfrom the main elongate body. The creating a second cavity step mayfurther comprise moving the excavation device longitudinally along abidirectional path approximating the first axis and adjusting theadjustment member to move the second end of the arm to at least one ofthe plurality of distances from the main elongate body such that theabrading surface removes bone material. The main elongate body maycomprise a rotational cutting tool having a first end, a second end, acutting region extending at least partially between the first end andsecond end, and a circumferential engagement member and the excavationdevice may further comprise a flexible drive train configured to engagethe circumferential engagement member. The placing an excavation devicestep may further comprise creating a pathway through cortical bone on atleast one side of the tibia, inserting the flexible drive train througha the pathway, and coupling the flexible drive train to the rotationalcutting tool so that movement of the flexible drive train causesrotation of the rotational cutting tool. The creating a second cavitystep may further comprise moving the circumferential engagement memberof the rotational cutting tool substantially towards one side of thetibia while the rotational cutting tool is being rotated by the flexibledrive train. The flexible drive train may be moved by drive unit. Therotational cutting tool may be used to create the first cavity. Therotational cutting tool may comprise a reamer. The first end of therotational cutting tool may comprise a blunt tip. The second end of therotational cutting tool may be coupled to a retrieval tether extendingfrom the first incision. The retrieval tether may be coupled to therotational cutting tool by a swivel joint. The removing step maycomprise removing the rotational cutting tool by applying tension to theretrieval tether from a location external to the patient. The method mayfurther comprise the step of creating an osteotomy between a firstportion and a second portion of the tibia, wherein the flexible drivetrain extends through the osteotomy.

In another embodiment, a method of implanting a non-invasivelyadjustable system for changing an angle of the tibia of a patientincludes creating an osteotomy between a first portion and a secondportion of the tibia; making a first incision in the skin of the patientat a location adjacent the tibial plateau of the tibia of the patient;creating a first cavity in the tibia along a first axis extending in asubstantially longitudinal direction from a first point at the tibialplateau to a second point; placing an excavation device within the firstcavity, the excavation device configured to excavate the tibiaasymmetrically in relation to the first axis; creating a second cavityin the tibia with the excavation device, wherein the second cavityextends substantially towards one side of the tibia; placing anon-invasively adjustable implant through the first cavity and at leastpartially into the second cavity, the non-invasively adjustable implantcomprising an adjustable actuator having an outer housing and an innershaft, telescopically disposed in the outer housing; coupling the outerhousing to the first portion of the tibia; and coupling the inner shaftto the second portion of the tibia. The first portion may be above theosteotomy and the second portion may be below the osteotomy. The firstportion may be below the osteotomy and the second portion may be abovethe osteotomy. The second cavity may communicate with the first cavity.The method may further comprise the step of non-invasively causing theinner shaft to move in relation to the outer housing. The non-invasivelyadjustable implant may comprise a driving element configured to move theinner shaft in relation to the outer housing. The driving element may beselected from the group comprising: a permanent magnet, an inductivelycoupled motor, an ultrasonically actuated motor, a subcutaneoushydraulic pump, a subcutaneous pneumatic pump, and a shape-memory drivenactuator.

In another embodiment, a method of preparing a bone for implantation ofan implant includes making a first incision in the skin of a patient;creating a first cavity in the bone by removing bone material along afirst axis extending in a substantially longitudinal direction from afirst point at the to a second point; placing an excavation devicewithin the first cavity, the excavation device including a main elongatebody and configured to excavate the bone asymmetrically in relation tothe first axis, the excavation device further comprising an articulatingarm having a first end and a second end, the arm including a compactionsurface; creating a second cavity in the bone with the excavationdevice, wherein the second cavity communicates with the first cavity andextends substantially towards one side of the bone; and removing theexcavation device.

In another embodiment, a method of preparing a bone for implantation ofan implant includes making a first incision in the skin of a patient;creating a first cavity in the bone by removing bone material along afirst axis extending in a substantially longitudinal direction from afirst point at the to a second point; placing an excavation devicewithin the first cavity, the excavation device including a main elongatebody and configured to excavate the bone asymmetrically in relation tothe first axis, the excavation device further comprising an articulatingarm having a first end and a second end, the arm including an abradingsurface; creating a second cavity in the bone with the excavationdevice, wherein the second cavity communicates with the first cavity andextends substantially towards one side of the bone; and removing theexcavation device.

In another embodiment, a method of preparing a bone for implantation ofan implant includes making a first incision in the skin of a patient;creating a first cavity in the bone by removing bone material along afirst axis extending in a substantially longitudinal direction from afirst point at the to a second point; placing an excavation devicewithin the first cavity, the excavation device including a main elongatebody and configured to excavate the bone asymmetrically in relation tothe first axis, the excavation device further comprising a rotationalcutting tool configured to be moved substantially towards one side ofthe bone while the rotational cutting tool is being rotated; creating asecond cavity in the bone with the excavation device, wherein the secondcavity communicates with the first cavity and extends substantiallytowards one side of the bone; and removing the excavation device.

In another embodiment, a system for changing an angle of a bone of asubject includes a non-invasively adjustable implant comprising anadjustable actuator having an outer housing and an inner shaft,telescopically disposed in the outer housing, the outer housingconfigured to couple to a first portion of the bone, and the inner shaftconfigured to couple to a second portion of the bone; a driving elementconfigured to move the inner shaft in relation to the outer housing; andan excavation device including a main elongate body configured to insertwithin a first cavity of the bone along a first axis, the excavationdevice configured to excavate the bone asymmetrically in relation to thefirst axis to create a second cavity communicating with the firstcavity, wherein the adjustable actuator is configured to be coupled tothe bone at least partially within the second cavity. The drivingelement may be selected from the group comprising: a permanent magnet,an inductively coupled motor, an ultrasonically actuated motor, asubcutaneous hydraulic pump, a subcutaneous pneumatic pump, and ashape-memory driven actuator. The excavation device may be configured tocompact cancellous bone. The excavation device may comprise anarticulating arm having a first end and a second end, the arm includingan abrading surface. The abrading surface may comprise a rasp. Theexcavation device may comprise a rotational cutting tool having a firstend, a second end, a cutting region extending at least partially betweenthe first end and second end, and a circumferential engagement member,and the excavation device may further comprise a flexible drive trainconfigured to engage the circumferential engagement member.

In another embodiment, a system for changing an angle of a bone of asubject includes a non-invasively adjustable implant comprising anadjustable actuator having an outer housing and an inner shaft,telescopically disposed in the outer housing, the outer housingconfigured to couple to a first portion of the bone, and the inner shaftconfigured to couple to a second portion of the bone; and a drivingelement configured to move the inner shaft in relation to the outerhousing, wherein the driving element is selected from the groupcomprising: a permanent magnet, an inductively coupled motor, anultrasonically actuated motor, a subcutaneous hydraulic pump, asubcutaneous pneumatic pump, and a shape-memory driven actuator. Thedriving element may comprise a permanent magnet.

In another embodiment, a system for changing an angle of a tibia of asubject having osteoarthritis of the knee includes a non-invasivelyadjustable implant comprising an adjustable actuator having an outerhousing and an inner shaft, telescopically disposed in the outerhousing, the outer housing having a first transverse hole, and the innershaft having a second transverse hole; a driving element configured tomove the inner shaft in relation to the outer housing, wherein thedriving element is selected from the group comprising: a permanentmagnet, an inductively coupled motor, an ultrasonically actuated motor,a subcutaneous hydraulic pump, a subcutaneous pneumatic pump, and ashape-memory driven actuator; a first anchor configured to place throughthe first transverse hole and to couple to a first portion of the tibia;and a second anchor configured to place through the second transversehole and to couple to a second portion of the tibia, wherein at leastone of the first anchor and second anchor is configured to be pivotablein relation to the non-invasively adjustable implant when coupled toeither the first portion or second portion of the tibia. The drivingelement may comprise a permanent magnet.

In another embodiment, a method of changing a bone angle includescreating an osteotomy between a first portion and a second portion of atibia of a patient; creating a cavity in the tibia by removing bonematerial along an axis extending in a substantially longitudinaldirection from a first point at the tibial plateau to a second point;placing a non-invasively adjustable implant into the cavity, thenon-invasively adjustable implant comprising an adjustable actuatorhaving an outer housing and an inner shaft, telescopically disposed inthe outer housing, and a driving element configured to be remotelyoperable to telescopically displace the inner shaft in relation to theouter housing; coupling one of the outer housing or the inner shaft tothe first portion of the tibia; coupling the other of the outer housingor the inner shaft to the second portion of the tibia; and remotelyoperating the driving element to telescopically displace the inner shaftin relation to the outer housing, thus changing an angle between thefirst portion and second portion of the tibia.

While embodiments of the present invention have been shown anddescribed, various modifications may be made without departing from thescope of the present invention. Any of the embodiments of thenon-invasively adjustable wedge osteotomy device may be used for gradualdistraction (Ilizarov osteogenesis) or for acute correction of anincorrect angle. The implant itself may be used as any one of theelements of the excavation device, for example, the external portion ofthe implant may have features that allow it to be used as a reamer, raspor bone compactor. As an alternative, remote adjustment described abovemay be replaced by manual control of any implanted part, for examplemanual pressure by the patient or caregiver on a button placed under theskin. The invention, therefore, should not be limited, except to thefollowing claims, and their equivalents.

It is contemplated that various combinations or subcombinations of thespecific features and aspects of the embodiments disclosed above may bemade and still fall within one or more of the inventions. Further, thedisclosure herein of any particular feature, aspect, method, property,characteristic, quality, attribute, element, or the like in connectionwith an embodiment can be used in all other embodiments set forthherein. Accordingly, it should be understood that various features andaspects of the disclosed embodiments can be combined with or substitutedfor one another in order to form varying modes of the disclosedinventions. Thus, it is intended that the scope of the presentinventions herein disclosed should not be limited by the particulardisclosed embodiments described above. Moreover, while the invention issusceptible to various modifications, and alternative forms, specificexamples thereof have been shown in the drawings and are hereindescribed in detail. It should be understood, however, that theinvention is not to be limited to the particular forms or methodsdisclosed, but to the contrary, the invention is to cover allmodifications, equivalents, and alternatives falling within the spiritand scope of the various embodiments described and the appended claims.Any methods disclosed herein need not be performed in the order recited.The methods disclosed herein include certain actions taken by apractitioner; however, they can also include any third-party instructionof those actions, either expressly or by implication. For example,actions such as “inserting a bone reamer into the first portion” include“instructing the inserting of a bone reamer into the first portion.” Theranges disclosed herein also encompass any and all overlap, sub-ranges,and combinations thereof. Language such as “up to,” “at least,” “greaterthan,” “less than,” “between,” and the like includes the number recited.Numbers preceded by a term such as “approximately”, “about”, and“substantially” as used herein include the recited numbers, and alsorepresent an amount close to the stated amount that still performs adesired function or achieves a desired result. For example, the terms“approximately”, “about”, and “substantially” may refer to an amountthat is within less than 10% of, within less than 5% of, within lessthan 1% of, within less than 0.1% of, and within less than 0.01% of thestated amount.

What is claimed is:
 1. A method of changing a bone angle, the methodcomprising: creating an open wedge osteotomy between a first portion anda second portion of a tibia of a patient, such that the first portion ofthe tibia remains hingedly attached to the second portion of the tibia,and an exposed surface of the second portion of the tibia opposes anexposed surface of the first portion of the tibia, wherein said exposedopposing surfaces are created by the open wedge osteotomy; creating anintramedullary cavity in the tibia by removing bone material along anaxis extending in a substantially longitudinal direction from a firstpoint at the tibial plateau to a second point; placing a non-invasivelyadjustable implant into the intramedullary cavity, the non-invasivelyadjustable implant comprising: an adjustable actuator having an outerhousing and an inner shaft telescopically disposed in the outer housing;an upper bracket attached to the inner shaft; and a magneticallyadjustable driving element configured to be remotely operable totelescopically displace the inner shaft in relation to the outerhousing; after placing the non-invasively adjustable implant in theintramedullary cavity coupling a lower bracket to the outer housing ofthe non-invasively adjustable implant and to the exposed surface of thefirst portion of the tibia created by the open wedge osteotomy; couplingthe upper bracket to the exposed surface of the second portion of thetibia created by the open wedge osteotomy; and remotely operating thedriving element to telescopically displace the inner shaft in relationto the outer housing, thus changing an angle of the open wedge osteotomydefined between the exposed opposing surfaces of the first portion andsecond portion of the tibia.
 2. The method of claim 1, wherein theremotely operating step increases the angle between the exposed opposingsurfaces of the first portion and second portion of the tibia.
 3. Themethod of claim 1, wherein the remotely operating step decreases theangle between the exposed opposing surfaces of the first portion andsecond portion of the tibia.
 4. The method of claim 1, wherein theremotely operating step is performed a plurality of times.
 5. The methodof claim 4, wherein the remotely operating step is performed a pluralityof times over of period of between one day and one month.
 6. The methodof claim 4, wherein a gap (G) measured at a medial edge of the osteotomyis increased a total of between 1 mm and 20 mm during the plurality oftimes.
 7. The method of claim 6, wherein the gap (G) is increased at anaverage gap increase rate (GIR) of less than or equal to two millimetersper day during the plurality of times.
 8. The method of claim 1, whereina gap (G) measured at a medial edge of the osteotomy is increased at apositive distance less than or equal to two millimeters during atwenty-four hour period.
 9. The method of claim 1, further comprising astep of monitoring the growth of bone via radiography.
 10. The method ofclaim 1, further comprising a step of allowing bone material toconsolidate between the first portion and second portion of the tibia.11. The method of claim 1, further comprising a step of surgicallyremoving the non-invasively adjustable implant from the tibia.
 12. Themethod of claim 1, wherein the implant further comprises aradially-poled permanent magnet and the method further comprises a stepof removing at least the radially-poled permanent magnet from thepatient.
 13. The method of claim 1, wherein the remotely operating step1 s performed with the patient awake.
 14. The method of claim 13,wherein the amount chosen to telescopically displace the inner shaft isat least partially determined by interpreting feedback from the awakepatient.
 15. The method of claim 1, wherein the driving elementcomprises a permanent magnet.
 16. The method of claim 15, wherein thepermanent magnet is a radially poled rare earth magnet.
 17. The methodof claim 15, wherein the remotely operating step further comprisesplacing an external adjustment device capable of causing a movingmagnetic field in the proximity of the patient and causing the permanentmagnet to rotate.